JP2009061719A - Copy protection paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To offer a copy protection paper that makes impossible to read characters or symbols printed on the documents when the documents are copied. <P>SOLUTION: The invention refers to a copy protection paper which is constructed by overlaying a printing undercoat layer 50 having printability quality on top of an aluminum vapor deposition sheet 30 which vapor deposits aluminum on a PET film 10 and wavy lines 51 are formed in printing on the printing undercoat layer 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a copy-preventing sheet for preventing the reading of characters / symbols printed on a document when the document is copied.

  Conventionally, copy prevention papers such as Patent Documents 1 and 2 have been proposed as papers for preventing confidential information such as personal information from being copied by a copying machine. This copy prevention paper is formed by superimposing a printing foundation layer having printability on an aluminum vapor deposition sheet obtained by vapor-depositing aluminum on a base sheet.

  By the way, in a copying machine, when copying a sheet, light is applied to the sheet to be copied, and a part of the diffusely reflected light is received by a fixed light receiving unit to acquire information printed on the sheet. ing.

When the above copy protection paper is copied with a copy machine, the light emitted from the light source of the copy machine causes a specular reflection on the aluminum vapor deposition surface, so that all the reflected light is directed in a specific direction. It is difficult for the light receiving unit to receive light. Therefore, the background of the copy becomes black. Since characters / symbols printed on copy protection paper are generally printed with black ink (toner), the copied characters / symbols will be the same black as the background color of the copy, and those characters / symbols will be printed. Cannot be distinguished from the background and becomes unreadable.
JP 2005-225088 A JP-A-8-39730

  By the way, when a person interprets a printed character / symbol, he / she visually recognizes the difference between the color of the character / symbol and the other part, that is, the background color, and outlines the character / symbol. Extracted and interpreted. For this reason, the smaller the density difference between the character / symbol color and the background color, the more difficult it is to interpret the character / symbol. Conversely, the greater the difference between the shades, the more the character / symbol is emphasized and the easier it is to interpret.

  However, in the above-described conventional copy protection paper, the background black color of the copied material becomes light under certain conditions, and the difference in color shade between the black color of the character / symbol increases and the character / There were times when the symbols were slightly readable. It has been confirmed that this problem is particularly likely to occur when copying using a color copier.

  The present invention has been completed based on the above circumstances, and an object of the present invention is to provide a copy prevention sheet that can further reduce the legibility of characters and symbols when copied.

  The present invention relates to a copy-preventing paper in which an aluminum vapor-deposited sheet obtained by vapor-depositing aluminum on a base material sheet and a print ground layer having printability are superimposed, and a ground pattern is formed on the print ground layer by printing. It has the feature in being.

  In the present invention, the background pattern may be formed by a line pattern or a character string, and the color of the background pattern is more preferably formed by white ink. Here, a preferable white system includes not only white but also gray and silver of various concentrations (particularly, matte is preferable).

  It is assumed that a copy (hereinafter referred to as “print original”) printed on a copy-preventing paper of the present invention by, for example, a laser printer is copied by a copying machine. Since the background portion excluding the background pattern and the printed character / symbol portion of the original print is an aluminum vapor deposition surface, it appears black in the copy. Further, the background pattern preprinted on the copy prevention paper and the characters / symbols printed by the printer appear at the same density.

  In general, since characters / symbols, etc. printed on a printing original are black, they are the same as the background (black) of a copy, and do not stand out from the background, so that the characters / symbols cannot be read.

  By the way, the background portion of the aluminum vapor deposition surface may not be completely black depending on the copying conditions, but may be copied in a dark gray color or a chromatic color close to black in a color copier, depending on the copying conditions. Then, there is a possibility that the outline of the character / symbol can be discriminated slightly due to the density difference between the light density background and the black character / symbol.

  However, since the background pattern is printed on the surface of the copy-preventing paper of the present invention, the background pattern can be seen in the copied material due to the density difference between the background color and the background pattern. Since the ground pattern and the characters / symbols are printed in an overlapping manner, the characters / symbols etc. that are observed slightly are as if they are seen through the ground pattern. For this reason, even if the outline of a line such as a character / symbol is observed due to a difference in density, it is disturbed by the ground pattern, so the outline is not connected and is not observed. It becomes difficult.

  In the state of the original printing, since the background pattern is printed on the aluminum vapor deposition surface in the present invention, the reflection of the aluminum vapor deposition surface is suppressed, and the printed characters / symbols are read with the glare reduced. It becomes easy.

  If a line pattern or character string is used as the type of ground pattern to be printed on copy-protected paper, the line pattern is simple because it is a simple pattern, and it is easy to create a character string by using an existing character font. Can be printed. In addition, when a line pattern is formed with a density or thickness such that several line patterns cross for one character, the lines constituting the characters / symbols are complicatedly divided by the lines constituting the line pattern, Furthermore, the legibility can be lowered.

  If the background pattern formed on the copy protection paper is formed with white ink, the entire background looks whitish, so when the print information is printed in black, the print information of the original print is emphasized and visibility is improved. . Furthermore, when a white background pattern is formed, if the black background pattern is printed in an overlapping manner, the legibility of the copied material can be further reduced.

An embodiment of the present invention will be described with reference to FIGS.
The copy prevention paper 1 of this embodiment has a five-layer structure. The manufacturing method is as follows. First, for example, an aluminum vapor-deposited sheet 30 in which the aluminum vapor-deposited layer 20 is formed by vapor-depositing aluminum with a thickness of 45 nm on one surface of a transparent PET film 10 having a thickness of 12 μm is prepared. Next, high-quality paper 40 having a thickness of 100 μm, for example, is bonded to the surface of the aluminum vapor-deposited sheet 30 on the side of the PET film 10 where aluminum is vapor-deposited with an adhesive 31. A printed foundation layer 50 is further formed on the surface of the aluminum vapor-deposited sheet 30 on the PET film 10 side. A schematic drawing of the cross-sectional structure of the completed copy protection paper 1 is as shown in FIG.

  Here, the printing foundation layer 50 is provided to improve the fixability of ink or the like, and a urethane-based vehicle is coated on the PET film 10 as a primer coat, and PVA, silica, and surface activity are coated thereon. It is formed by coating a composition liquid in which four types of agent and water are mixed. Since the printing foundation layer 50 and the PET film 10 are transparent, the aluminum vapor deposition surface of the aluminum vapor deposition layer 20 under the two layers can be seen through.

  The above-described paper is cut into, for example, A4 size, and white wavy lines 51 are printed on the entire surface at regular intervals as a ground pattern on the printing base layer 50 as shown in FIG. For example, the wavy line 51 has a wavelength of about 20 mm, an amplitude of about 2 mm, and a line width of about 0.3 mm, and is printed continuously from end to end in the horizontal direction of the paper. A large number of wavy lines 51 are arranged at equal intervals in the vertical direction of the paper, and this interval is preferably set to an interval (for example, about 1 to 2 mm) that overlaps two to three with respect to the printed characters. .

  Next, a method for using the copy prevention paper 1 of this embodiment will be described. Assume that an address book is printed on the copy prevention paper 1 by using, for example, a black toner with a laser printer (print original). Since innumerable wavy lines 51 are printed as a background pattern on the copy prevention paper of the present embodiment, the printed original is printed so that characters / symbols constituting address information are superimposed on the wavy lines 51 group.

  In the original printing using the conventional copy protection paper 1, depending on the angle at which the document is viewed, there is a case where it feels dazzling due to reflection from the aluminum vapor deposition surface and it is difficult to read characters or the like.

  However, in the printing original using the copy prevention paper 1 of the present embodiment, since the wavy lines 51 are printed on the aluminum vapor deposition surface, the reflection of the metal color is suppressed, so that the glare is alleviated and easy to read. Become. Moreover, since the wavy line 51 is printed with white ink, the background of the character looks white and gray, and the visibility of the character and the like is improved by contrast with the black character. In addition, how the above-mentioned printed original appears is schematically illustrated in FIG. In FIG. 2, the aluminum vapor deposition surface is shown with a thin grid-like hatching.

  On the other hand, it is assumed that a copy is made by copying the original print with a copying machine. Since the background portion excluding the wavy line 51 and the printed character / symbol portion of the original print is an aluminum vapor deposition surface, it appears black in the copy. Further, the wavy lines 51 appear as white wavy lines as they are, and the printed characters and symbols appear black as they are. The overall appearance of this copy is schematically depicted in FIG.

  In this way, the characters / symbols, etc. printed on the original print are black, which is the same as the background, and therefore do not come out of the background. Of the lines constituting the characters / symbols, etc., the portions on the wavy line 51 (the lines intersecting the wavy line 51) are such that the character / symbol is white because the wavy line 51 is white. That portion is clearly distinguished from the wavy line 51. However, since the wavy line 51 has a linear shape, only the intersections with the lines constituting the characters / symbols are distinguished, and as a result, the lines constituting the characters / symbols are divided in some places. Observed and cannot be interpreted as letters and symbols after all (see FIG. 4).

  On the other hand, depending on the copy conditions, the background of the copy (the portion where the aluminum vapor-deposited surface is copied) is not completely black, and may be copied with a slightly low density black or a chromatic color close to black. In this case, the line of characters / symbols may be slightly visible due to the density difference between the black lines constituting the characters / symbols and the background. If the conventional copy protection paper without the line pattern 51 is formed as shown in FIG. 5, the character “A” may be deciphered.

  However, in the copy prevention paper of this embodiment, innumerable wavy lines 51 are printed on the surface, so that a wavy line 51 (line pattern) can be seen even in a copy due to a density difference between the background color and the wavy line 51. . Since the line pattern and the characters / symbols are overprinted, the characters / symbols etc. that are observed slightly appear as if they are seen through the line pattern as shown in FIG. . For this reason, even if the outline of a line such as a character / symbol is partially observed due to the difference in density, it is disturbed by a large number of wavy lines 51 (line patterns), so that the outline is connected and not observed.・ It becomes extremely difficult to interpret as symbols.

  As described above, according to the present embodiment, the legibility of characters / symbols can be greatly reduced even if the density of the background in the copy is reduced while improving the legibility of letters / symbols in the original print. it can.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the present embodiment, the white wavy line 51 is printed as the ground pattern, but a line pattern other than the wavy line may be used. For example, a black character string whose density can be adjusted by forming it with halftone dots, a line pattern similar to the wrinkle pattern shown in FIG. 7 (a copy thereof is shown in FIG. 8), or a simple lattice pattern may be printed. Good.

  (2) The place where the background pattern is printed may be printed in advance on the entire surface of the copy-preventing paper. If the place where the print information to be copied is to be printed is determined in advance, the place is printed only on that part. A pattern may be printed.

  (3) In this embodiment, an example is shown in which an address is printed by a printer as information for which copying is to be prevented. However, it is needless to say that the present invention can be applied to other copy-preventing paper on which printing information for which copying is to be prevented is printed.

  (4) In this embodiment, the printing foundation layer is formed by coating a solution mainly composed of PVA, but this may be a printing foundation layer corresponding to the printing method to be applied.

  (5) In this embodiment, high-quality paper is laminated on the aluminum vapor-deposited sheet. However, the present invention is not limited to this, and the base sheet of the aluminum vapor-deposited sheet has strength, flexibility, etc. suitable for handling such as printing. If it is, it is not always necessary to laminate quality paper.

  (6) In the present embodiment, only one type of white line pattern is formed, but in addition to this, a ground pattern of the same color or other colors (white or black with different densities) may be formed in an overlapping manner. This can further reduce the legibility of characters, symbols, etc. in the copy.

Sectional drawing showing the layer structure of the copy protection paper which concerns on one Embodiment of this invention The top view which shows the state printed on the copy protection paper of this embodiment Plan view showing a copy of the original print An enlarged plan view showing an enlarged portion of characters in a copy An enlarged plan view showing an enlarged portion of a character when the background density is low in a copy obtained by copying a conventional copy prevention paper An enlarged plan view showing an enlarged portion of a character when the background density is low in a copy Plan view of copy protection paper showing another embodiment with different ground patterns The top view of the copy which copied the copy prevention paper which shows other embodiment which made the ground pattern different

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... PET film 30 ... Aluminum vapor deposition sheet 50 ... Printing foundation layer 51 ... Wave

Claims (5)

  A copy-preventing paper in which an aluminum vapor-deposited sheet obtained by vapor-depositing aluminum on a base sheet and a printable base layer having printability are overlaid, a ground pattern is formed on the print base layer by printing. And copy protection paper.   The copy protection paper according to claim 1, wherein the ground pattern is formed by a line pattern.   2. The copy prevention paper according to claim 1, wherein the ground pattern is formed by a character string.   4. The copy prevention paper according to claim 1, wherein the ground pattern is formed of white ink.   5. The copy protection paper according to claim 4, wherein the ground pattern is formed by overlapping a white ink and a black ink.

Images